Connected: An Internet Encyclopedia
RFC 1332 - 2. A PPP Network Control Protocol (NCP) for IP

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### 2. A PPP Network Control Protocol (NCP) for IP

The IP Control Protocol (IPCP) is responsible for configuring, enabling, and disabling the IP protocol modules on both ends of the point-to-point link. IPCP uses the same packet exchange machanism as the Link Control Protocol (LCP). IPCP packets may not be exchanged until PPP has reached the Network-Layer Protocol phase. IPCP packets received before this phase is reached should be silently discarded.

The IP Control Protocol is exactly the same as the Link Control Protocol [1] with the following exceptions:

Data Link Layer Protocol Field

  Exactly one IPCP packet is encapsulated in the Information field of PPP Data Link Layer frames where the Protocol field indicates type hex 8021 (IP Control Protocol).

Code field

  Only Codes 1 through 7 (Configure-Request, Configure-Ack, Configure-Nak, Configure-Reject, Terminate-Request, Terminate-Ack and Code-Reject) are used. Other Codes should be treated as unrecognized and should result in Code-Rejects.

Timeouts

  IPCP packets may not be exchanged until PPP has reached the Network-Layer Protocol phase. An implementation should be prepared to wait for Authentication and Link Quality Determination to finish before timing out waiting for a Configure-Ack or other response. It is suggested that an implementation give up only after user intervention or a configurable amount of time.

Configuration Option Types

  IPCP has a distinct set of Configuration Options, which are defined below.

2.1. Sending IP Datagrams

Next: 2.1. Sending IP Datagrams

Connected: An Internet Encyclopedia
RFC 1332 - 2. A PPP Network Control Protocol (NCP) for IP